Sri Aurobindo
Letters of Sri Aurobindo
3. The Mother and the Practice of the Integral Yoga
These things that come to frighten you are merely impressions thrown on you by small vital forces which want to prevent you (by making you nervous) pushing on in sadhana. They can really 
do nothing to you, only you must reject all fear. Keep always this thought when these things come: “The Mother’s protection is with me, nothing bad can happen”; for when there is the psychic opening and one puts one’s faith in the Mother, that is sufficient to ward these things off. Many sadhaks learn, when they have alarming dreams, to call the Mother’s name in the dream itself and then the things that menace them become helpless or cease. You must therefore refuse to be intimidated and reject these impressions with contempt. If there is anything frightening, call down the Mother’s protection.
The heat you felt was probably due to some difficulty in the force coming down below the centre between the eyes where it has been working up till now. When such sensations or the unease you once felt or similar things come, you must not be alarmed, but remain quiet and let the difficulty pass.
What you had before that, the moonlight in the forehead, was this working in the centre there between the eyebrows, the centre of the inner mind, will and vision. The moonlight you saw is the light of spirituality and it was this that was entering into your mind through the centre, with the effect of the widening in the heart like a sky filled with moonlight. Afterwards came some endeavour to prepare the lower part of the mind whose centre is in the throat and join it with the inner mind and make it open; but there was some difficulty, as is very usually the case, which caused the heat. It was probably the fire of tapas, Agni, trying to open the way to this centre.
The experience of being taken up into the sky is a very common one and it means an ascent of the consciousness into a higher world of light and peace.
The idea that you must go more and more within and turn wholly to the Mother is quite right. It is when there is no attachment to outward things for their own sake and all is only for the Mother and the life through the inner psychic being is centred in her that the best condition is created for the spiritual realisation.
11 November 1935